Plants of South Eastern New South Wales
Myriophyllum alpinum
Common name
Alpine Water-milfoil
Family
Haloragaceae
Where found
Aquatic in high-altitude lakes and streams. Forms densely interwoven masses in relatively deep water. Mostly Kosciuszko National Park, the mountains to the north, and ACT. Occasionally elsewhere.
Notes
Perennial herb, rooting at the lower nodes, hairless. Stems to 0.5 m long, 1–2 mm in diameter, tangled. Leaves above the water in tufts at the tips of the stems, reddish, in whorls of 3-4, about 0.5 cm long, 3-5 mm wide, deeply dissected into 6–9 segments like a toothbrush, or leaves about 3.5 cm long, 1 mm wide, toothed and not dissected. Submerged leaves in whorls of 3-4, about 0.5-1.5 cm long, comb-shaped, with 6–9 linear segments. Male and female flowers on the same stem. Male flowers with 4 red to yellow hooded petals 2.9–3.5 mm long. Female flowers with 0 sepals, 0 petals, stigmas white. Flowers single at the base of whorled leaves.
All native plants on unleased land in the ACT are protected.
Rare Vic.
Definite identification of species of Myriophyllum often requires microscopic examination of the seed cases, beyond the scope of this key.
PlantNET description: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Myriophyllum~alpinum (accessed 24 January, 2021)
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